Existing and emerging consumer applications have created an increasing need for real-time three-dimensional (3D) imagers. These imaging devices, also commonly known as depth sensors or depth mappers, enable the remote measurement of distance (and often intensity) of each point on a target scene—so-called target scene depth—by illuminating the target scene with one or more optical beams and analyzing the reflected optical signal.
Various methods are known in the art for generating light sources based on arrays of multiple light-emitting elements of optical radiation on a monolithic semiconductor substrate.
United States Patent Application Publication 2014/0211215, whose disclosure is incorporated herein by reference, describes an optical apparatus, which includes a beam source configured to generate an optical beam having a pattern imposed thereon. In one embodiment, an optoelectronic device comprises a semiconductor die on which a monolithic array of vertical-cavity surface-emitting laser (VCSEL) diodes is formed in a two-dimensional pattern that is not a regular lattice. The term “regular lattice” means a two-dimensional pattern in which the spacing between adjacent elements in the pattern (for example, between adjacent emitters in a VCSEL array) is constant and is synonymous with a periodic lattice. The pattern can be uncorrelated, in the sense that the auto-correlation of the positions of the laser diodes as a function of transverse shift is insignificant for any shift larger than the diode size. Random, pseudo-random, and quasi-periodic patterns are examples of such uncorrelated patterns.